Sewing machine



Jan. 13. 1925. 1,522,782

, H. W. KRAG SEWING MACHINE Filed Feb. 2, 1923 2 I uerz tor 2 *afi'ifl His fiiiorneus Patented Jan. 13, 1925.

warren s 'rarss Parser orrice.

HARRY W. KRAG, OF ST. LOUIS, MISSO'UBI,,ASSIGNOR T AMERICAN SHOE MACHIN- ERY & TOOL COMPANY, OF ST. LOUIS, MISSOURI.

SE'WING MACHINE.

Application filed February 2, 1923. Serial No. 616,586.

T 0 all whom it may concern:

Be it known that I, HARRY WV. KRAG, a citizen of the United States, and a resident of the city of St. Louis, and State of Missouri, have invented a new and useful Tmprovement in Sewing Machines, of which the following is a specification.

This invention relates principally to sewing machines of the waxed-thread type employing a needle-feed mechanism having a needle operating in front of a bobbin case which is removably mounted in a rotary shuttle.

The principal object of the present 111" vention is to provide for the ready insertion or removal of the bobbin case without dismounting the needle. Other objects are simplicity of construction, cheapne ss of manufacture and compactness of design.

The invention consists principally in pro viding the needle-feed mechanism with means for shifting the needle clear of the bobbin case to permit removal and'replacement of said bobbin case; and it also con sists in the combinations and arrangements of parts hereinafter described and claimed.

In the accompanying drawing, wherein like numerals refer to like parts wherever they occur,

Fig. 1 is a front view of a portion of a sewing machine provided with a needleshifting mechanism embodying my invention;

Fig. 2 is a similar view showing the positions of the parts after the throw-out arm has been actuated to move the needle to a position that will permit withdrawal and replacement of the bobbin case.

Fig. 3 is a horizontal section on the line 33 in 1; and

Fig. 4 is a vertical section on the line 4-4 in Fig. 1. I

Referring to the accompanying drawlng, my invention is shown in connectlon with the needle feed mechanism of a waxedthread sewing machine comprising a shuttlehead 4, a needle-plate or work-support 5 and a bobbin-case 6 removably mounted in a rotary shuttle 7. This mechanism is wellknown and it is considered unnecessary to illustrate it in detail.

7 Mounted on the front of the machine, be-

low the shuttle-head 4, is a horizontally reciprocative feed-slide 8 which slidably supports a vertically reciprocative needle-bar 9.

withdraw from the work, by means of a horizontal rock-arm 12. This rock-arm is adapted to be swung vertically in any desired manner (not shown) and has a suitable block-and-pin connection at its free end with the lower end portion of said needle-bar. The rear face of the feed-slide 8 is formed with a. horizontally extending undercut rib 13 that fits within a horizontally extending undercut slideway 14 formed in a lateral extension 15 of the shuttle-head 4. The feed-slide 8 is reciprocated horizontally, to cause the needle'supported thereon to feed the work, by means of a suitable needlefeed mechanism comprising a feed-segment 16 supported on the forward end of a rockshaft 17, which is journaled in a horizontal bearing 18 at one side of the shuttle-head and is adapted to be actuated in any desired manner (not shown). The feed-segment 16 "is provided in its front face with an arcuate slideway 19 adapted to receive a slideblock 20 mounted on one end of a. link 21, whose opposite end is pivotally secured by means of a cap screw 22 to a crank-arm 23 that pro ects radially from the rear end of n rock-shaft 24 journaled in a horizontal bear- 'ing 25 formed in the feed-slide 8.

The

arcuate slideway 19 is described around the axis of the rock-shaft 24 as a center and provided at its upper and lower ends with stop-pins 19 which serve to retain the slideblock 20 within. said arcuate slideway. The

rock-shaft 24 is disposed parallel with the s wing 27 whose rear end abuts a ainst a shoulder on said plunger and whose forward end abuts against a shoulder formed in the forward end portion of the bore in the rockshaft 24. This spring serves to normally hold the spring-pressed plunger 26 with its rear end portionentered withinthe hole P un er 126 n e ided wit a kno whereby said plunger may be withdrawn dfiom the hol e in the-link 21. A throwont ar 2, e stendsi erizenta y ace th fron ,face oftl e feed-slideand hasone end keyed or otherwise rigidly secured to the forward and 0f illel 'llef 2 be -Wee t k ob or handle 28 r the spring-pressed plunger 26 and the bearing for; said roclpshaft. Movement of the operating arm 29 longitudinally of the rockshaig't Qtis prevented by n eansof a' clampingscrew29 which cngages the split hub portion of Sitld arm. The free endjof the throw-out lever 29 s provided with a spring-pressed latch-pin adapted to' enter within any of aseries of holes 5 1 formed in the adjacent front l m bf the f d-Slid -.W holes ar ranged on an ,arc ,of a circle described around the pivotal axis of "the throw-out lever. By this arrangement, the engagement of the latch-pin 3.0 with any one of .the series of holes 31 intheieed-slide serves to lockthe thro -w-outarm 29fand the con 7 ecting link 2J1 in;the desired angular posions Th 1 ine press vlat hp a th free end of the :throw outlever is preferably provided with a handle or knob 32, whereby said pinmay be readily withdrawn from one of the slots .31 and the throw-out lever swung to a position that will cause said latchpin to engage :a difl'erent hole.

Thi ans dnth angula pos t on o t throwout lever lengthens or shortens the horizontal movement of the feed-slide, whereby the length of stitch maybe varied.

\Vhen it .is desiredto remove thebobbin case, the spring-pressed plunger 26 and the spring-pressed latch-pin 30 are withdrawn from;thefholesengaged thereby in the link .21 .an d t-he feed-slide 8, respectively. The

throw-out arm is then swung anti-clockwise ste -as pes l Wh ch a z o 'rota sr rock fshaft 24 and causes the oranlearm 23 thereof to carry with it the end of thecon- 'ne tinglink-QL During this movement the entireieed-slide is forced to move to the left a distance that is twice the throw of the crank arm 23, which movement is sufficient to shift the needle carried by said feedslide to one side of the bobbin case and thereby permit saidbobbin case to be withdrawn from the shuttlehea'd. After the bobbin case is replaced, the thl'0\V' OUt arm of said link fandsaid crank-arm, at ng fixed to St-11d rockshatt, a springis turned to its normal position, during which time the:. spring-pressed [plunger 26 and the spring-pressed latch-pin 30 enter into the holesprovided' therefor in the link 21 feed-slide 3 8, thereby locking said link and said'operating arm in their positions. I

It is obvious that numerous changes may .ben ade without departing from the invention, and I do not wish to be limited to the precise construction shown and described. Wha I claim i r -1. A sewing machine comprising a remo b y lmquet ibehbin' ca .11 7 on lly r mimcatlv ne dle l e fi llg 1 ;front ofsaidbobbin case means forimpartg su ovemen eedsmeans' ass nted withis d need a tuatin eneei s fe h 11 g aid-need t0 111 5 916 eisa dib b cas t pe i r eva a d jren ee n eet-e' the latter.

2A S wing eehineyc mp isi e li movably mounted bobbin case ahonzontally reciprocative feed-slide having a normally limited I stroke, means normally c onnested withsaid feed slide for actuating the same, a needle ,mountedionsaid feed-slide and operating in front of said Qbobbin case,

nd m a for s on ec ng Said t' e r slid fromthe actuat1ng' means there'iEo-r whereby said feed sIide is adapted toibe moved ajdistam f cien ite.s ift h wneetl h ell 1 on side 1 said bob n; ase

. 'Aseii ng hi 'eempriein re ably support d ib bl in ase a liqr i f y a eipl'e tiv feed-s i ha i ane e' l e 0P1- shaft ie rna in i Said t ed-s d ai d h ving a crank-arm, a horizontally reciproca- V ;t1ve link hav ng a ,plvotal connection with sa d, crank arm, neans normally engaged wit eiFl,=- 11 .i'Qr prev n i swin i movement of said link with relation to said cra -arm mean 011 seidri eekrehafb 1 n ally engaged with said feed-slide for pre- .'as n if enb j s dlbeb in a y reels venting the rooking moven ent otsaidzrockjshaft, andrneans gifor disengaging said @lirik engaging means and said feed-slide engagrespectively whereby said rock-shaft is adapted tobe, actuated toilengthenthe stroke of said feed-slide. r

4:. A sew ng machine comprisingalremow ab y suppe it ed e b e o zon l y reeiprocative feed-slide carrying a needle operating in front ofsaid'bobbin'casefarock-shaft journaled in said feed-slideiand having acrank-arm, a horizontally reciprocative linkhaving one end pivotally connected "to sald crank-arm, a spring-pressed plunger axially dispose d withinsaid rockshaf -an a ap ed to n rma y e ag sa link to prevent relative swinging movement a P ing means from said link and saidieed slide,

i l i ll pressed latch-pin mounted on said operating arm and adapted to normally engage said v feed-slide to hold said arm in position and to prevent rocking movement of said rockshaft, said plunger and said latch-pin being adapted to be disengaged from said link and said feed-slide, respectively, whereby said operating arm is adapted to be actuated to rock the rock-shaft and thereby lengthen the stroke of said feed-slide.

5. A sewing machine comprising a removably supported bobbin case and a horizontally reciprocative feed-slide carrying a needle operating in front of said bobbin case, a rock-shaft journaled on a horizontal axis in said feed-slide and having a crankarm, a horizontally reciprocat-ive link pivotally connected at one end to said crankarm, and an oscillatory feed-segment operatively engaging the other end of said link to reciprocate the same, a spring-pressed plunger axially disposed within said rockshaft and adapted to normally engage a hole in said link to prevent relative swinging movement of said link and said crank-arm, an operating arm fixed to said rock-shaft, a spring-pressed latch-pin on said arm and adapted to normally engage a hole in said feed-slide to prevent swinging movement of said operating arm and rocking movement of said rock-shaft, and knobs on the forward ends of said plunger and said latch-pin to permit said members to be disengaged from said link and said feed-slide whereby said arm is adapted to be actuated to rock said rook-shaft and thereby lengthen the stroke of the feed-slide Signed at St. Louis, Missouri, this 31st day of January 1923.

HARRY W. KRAG. 

